This invention relates to a lithium ion sensor and more particularly, to a lithium ion sensor for measuring a lithium ion concentration in circulatory organs in a body which changes upon administration of lithium carbonate used in a therapy for manic depressive psychosis.
In pathologic physiology of manic depressive psychosis, it is found that depression is caused by reserpine which drains intracerebral monoamine and a medicine (thymoleptics) for depression enhances an effect of monoamine. Therefore, a monoamine hypothesis assumes that depression is caused when one or both of noradrenaline and serotonin are reduced and mania is caused when they are increased. However, analysis of blood, urea, bone marrow fluids, and brain tissues of patients has not provided any definite evidence supporting this hypothesis to date. Therefore, lithium carbonate is often used to cure depression because it is assumed to suppress effects of intracerebral monoamine and serotonin.
Detection of a lithium ion concentration and its change in circulatory organs in a body caused by lithium carbonate is essential in determining the cause of manic depressive psychosis or developing a medical treatment therefor. However, a lithium ion sensor having a high response speed and good precision has not been available yet. In addition, a demand has arisen for a sensor which can be safely used for continuous measurement in circulatory organs or a body over a long time period and which has stable characteristics.